Abstract
KEY POINTS: Population-based retrospective cohort study to evaluate clinical correlates of gout and its impact on patients undergoing chronic dialysis. 13.5% of US dialysis-dependent patients had gout and were older and male, with a higher prevalence of hypertension and cardiovascular disease. Gout diagnosis was associated with a higher incidence of cardiovascular conditions, levels of anemia, hospitalization, and mortality. BACKGROUND: An association between gout and nondialysis chronic renal disease has long been recognized, yet limited research exists regarding prevalence, treatment, anemia management, and outcomes in patients with ESKD undergoing dialysis. METHODS: Using data from United States Renal Data System, we conducted a population-based retrospective cohort study in adult patients covered by Medicare and on dialysis in 2017. Multivariate logistic regression models were used to estimate potential factors and odds of gout diagnosis. Antigout medications and impact on anemia management were assessed and compared between gout and nongout dialysis patients using descriptive and regression analyses. Associations for all-cause mortality and cardiovascular-related hospitalizations during 1 year of study follow-up were compared between gout and nongout patients using multivariate Cox regression models. RESULTS: Of 231,841 ESKD Medicare patients in 2017 undergoing continuous dialysis, 31,300 (13.5%) had one or more gout diagnostic code(s). Increased odds of having a gout diagnosis were independently associated with older age, male sex, Asian race, obesity, hypertension, and cardiovascular disease. Gout diagnosis was associated with higher prevalence for anemia as indicated by increased erythropoietin-stimulating agent requirements (odds ratio=1.18 for high versus low erythropoietin-stimulating agent dose, 95% confidence interval [95% CI], 1.14 to 1.22) and likelihood of blood transfusions (odds ratio=1.34, 95% CI, 1.30 to 1.38). During the 1-year study follow-up, mortality among gout versus nongout patients was higher by 3% (95% CI, 0 to 6) and a composite association of mortality and cardiovascular disease hospitalization was higher by 6% (95% CI, 3 to 9) after adjusting for comorbid conditions. CONCLUSIONS: A gout diagnosis was found in 13.5% of US dialysis-dependent patients and was associated with a higher burden of comorbid cardiovascular conditions as well as an elevated incidence of hospitalization and mortality. These observations improve our current understanding of gout among the dialysis population and highlight the importance of new and better treatments to improve outcomes.